Kirkpatrick’s Decision Prompts Ratings Changes in Two Arizona Races

May 26, 2015 · 1:00 PM EDT

Up to this point, McCain was considered a heavy favorite for re-election to a sixth term, in part because the senator has proven to be a tough campaigner. Moreover, Republicans have carried The Grand Canyon State in the last four presidential elections, and Democrats haven’t won an Arizona Senate race since 1988. But Kirkpatrick could be a formidable foe who is credible enough to attract attention from donors beyond Arizona and Democratic outside groups.

There is still plenty of time for the race to evolve, including other Democrats potentially jumping in and a potential primary challenger to McCain, but the race looks more competitive than it was before Kirkpatrick’s announcement (which was first reported by Roll Call). We’re changing our rating from Republican Favored to Lean Republican.

Kirkpatrick leaves behind a very competitive House seat that will be challenging for Democrats to defend.

Mitt Romney won the 1st District, 50 percent to 48 percent, in 2012, and McCain won it 51 percent to 48 percent in the 2008 presidential race. Kirkpatrick won re-election last cycle in the face of a challenging electoral environment. But her challenger, state Speaker Andy Tobin, barely made it through the late GOP primary and had difficulty raising money.

Since Kirkpatrick made her announcement earlier this morning, the candidate fields to replace her have barely started to take shape. And there is a chance that the shape of the district could change in response to the upcoming Supreme Court decision. But overall, without Kirkpatrick running for re-election, we’re changing our rating from Lean Democratic to Pure Toss-Up.